While I agree with the other posters that you need to follow up with the school and admit to an honest mistake - I also feel that you need to follow up in writing vs a phone call. If you do handle it by phone, please ask for the AO’s contact info and then send a confirmation email of your conversation to the AO to have it on record. AO’s change and just for peace of mind, you should have confirmation in writing.
You sound like a qualified candidate and congrats on the ED acceptance.